Horse-racing tycoons John Magnier and JP McManus have sold an office and retail building on Place Vendome in Paris to Norway’s oil-rich sovereign wealth fund for €1 billion.

The duo bought the Vendome Saint-Honoré property in 2007 for €650 million from Hammerson plc and Axa’s real estate management unit. They subsequently spent a considerable sum refurbishing the building.

Norges Bank Real Estate Management, part of the world’s biggest wealth fund, said it had bought the property from Trajan Luxembourg Sarl and Trajan Luxembourg II Sarl, both controlled by Mr Magnier and Mr McManus.

The Norwegian buyer approached the Irish businessmen and offered to buy the property, which was not put on the market. The sides signed and completed the agreement on Friday.

Norges said that it did not borrow to fund the deal and that the asset would be held “unencumbered by debt”.

Mr Magnier is best-known as head of Coolmore, the Tipperary-headquartered stud and racehorse breeding giant with operations in the Republic, US and Australia, which he runs with businessmen Michael Tabor and Derrick Smith.

Mr McManus has a range of interests, including a currency trading operation in Geneva, Switzerland. He owns a large number of mainly national hunt racehorses in both Ireland and Britain.

Norges Bank is a $780 billion fund that the Norwegian state uses to invest the country’s income from oil and gas production in the North Sea in stocks, bonds and property.

It made its first move into property in 2011 and about 3 per cent of the fund is now in real estate. It owns buildings in New York, London and Paris and is also seeking to expand into Asia.

Norway earns cash from its petroleum reserves by taxing production and through direct involvement in the industry. It also requires oil and gas found in its territorial waters to be processed in the Scandinavian country.